1. Field of the Invention
The present invention generally relates to plumbing systems and, in particular, to leakage test fittings for plumbing systems.
2. Description of Related Art
Municipality building codes generally require building contractors and/or plumbing sub-contractors to test plumbing systems for leaks either by a water test (i.e., a hydrostatic test) or by an air test (i.e., a pneumatic test) in accordance with the Uniform Plumbing Code. Leakage testing of installed plumbing networks, however, commonly is a grueling task for plumbing contractors. Plumbing networks typically wind through multiple stories of a building and have numerous possible sources of leaks at the interconnections between pipe sections and elbows, valves, or like junctions. Conventional leakage testing methods also are time consuming, dirty, wet and often hazardous.
A prevalent leakage testing method involves removing a short section of pipe at the base of the pipe system and replacing the pipe section with a T-joint. A plumber subsequently inserts a pre-formed inflatable rubber balloon or "test plug," connected to a retention chain, into the center opening of the T-joint, and inflates the balloon to block the fluid flow through the test pipe. The plumber then fills the pipe system above the inflated balloon with water and inspects the pipe system for leaks.
This leak testing procedure, however, suffers from several drawbacks. The standing column of water above the inflated balloon exerts a substantial amount of pressure on the balloon during the inspection process. Because the balloon can only withstand limited pressure without bursting, this method is restricted to testing a maximum of four or five floors (i.e., about 40 feet (12.2 meters) in height). Even when testing just a few floors, about 20 percent of the balloons rupture due to fatigue, causing substantial flooding and damaging the building. Such flooding is especially problematic and costly when occurring in multiple story buildings where the contractor is simultaneously finishing the lower floors with dry-wall, cabinetry, carpeting, etc.
Additionally, under-inflated balloons cannot support the water column in the pipe system; if the balloon retention chain breaks, the resultant water flow carries the balloon into the pipe system well below the T-joint. The balloon commonly lodges somewhere in the pipe system, blocking the pipe. A plumber then must determine where the balloon lodged in the plumbing network and remove the balloon by disassembling that portion of the network, a tedious and time-consuming process.
Plumbers also have injured their hands and fingers while attempting to remove the inflated balloons. In cases where the retention chain breaks, the chain has whipped and has severely injured the face and/or eyes of the plumber.
A number of prior plumbing test fittings have been developed to overcome the aforementioned problems associated with the use of an inflatable balloon in leakage testing plumbing networks. For instance, U.S. Pat. No. 3,941,156 issued to Metzger discloses a plumbing test fitting with a closure plate extending across the fitting, and a valve in communication with the test pipe chamber above the closure plate U.S. Pat. No. 4,932,241, issued to Carmody, et al., discloses a similar plumbing test fitting comprising a section of pipe with two chambers separated by a fixed closure plate. Water is introduced into the pipe system through an upper port in the test fitting to fill the pipe network above the closure plate. The system is then inspected for leaks, preferably through the use of a pressure gauge attached to the fitting. The pipe system is then drained by connecting the upper port via a bypass hose to a lower port in communication with the bottom end of the test fitting.
Both prior plumbing test fittings disclosed by the Metzger and Carmody, et al., patents unfortunately require removal of the test fitting and installation of an ordinary pipe section after the testing procedure to return the piping system to its original flow capacity. Installation and removal of these prior test fittings are laborious tasks, and flooding commonly occurs when removing these test fittings which typically damages the floors below. These devices also do not provide a means for testing the joints between the pipe network and the ordinary pipe section replacing the test fixtures. Thus, these devices do not allow the plumber to test all junctions or the plumbing network. Moreover, these prior test fittings are overly complicated and thus costly.
U.S. Pat. No. 3,045,706 to Dillon discloses an in-line valve designed primarily to stop fluid flow while servicing downstream equipment. The valve includes a solid "lamb chop" shaped plate which a plumber rotates across the pipe to stop fluid flow. Use of the apparatus is burdensome, because a series of screws must be loosened to allow the plumber to rotate plate into the closed position. The plumber must then tighten the screws to create a sealed system in the closed position. The plumber must again loosen the screw and rotate the plate into the open position, and then tighten the screws to create a sealed system in the open position.
Thus, a need exists for a simple, effective and ergonomic leakage test fitting which permits ready testing of a pipe network.